In default configuration (i.e. without /etc/adobe/mms.cfg file) Adobe Flash Player 11.2 has the following problems in Linux with NVIDIA drivers:

1) People's skin is blueish, people look like smurfs. Bug report, another bug report (Adobe cannot or more likely doesn't want to reproduce this bug - there's still a possibility that it's indeed NVIDIA's drivers bug).

2) YouTube videos leak through black parts of other windows (Adobe is aware of this bug but they don't want to fix it).

3) Watching YouTube videos causes Flash player to hang, crash the browser or freeze X.org server (A bug in X.org server or NVIDIA drivers as both sides blame each other).

4) It's impossible to read some websites which contain Flash charts. Just open this page and try to smooth scroll it in Mozilla Firefox. CPU usage will jump to 100%, the whole image on the display will be garbled (Most likely a bug in the interaction of X.org server and NVIDIA drivers).

This will cause the resulting trace library to change the VDPAU behavior of any clients that have tracing enabled, so make sure you only enable tracing for the web browser that loads the Flash plugin (eg. for Firefox in Ubuntu, you'd add an "export VDPAU_TRACE=1" line to /usr/lib/firefox-n.n/firefox.sh). Trying to use tracing on any other VDAU client after this has been installed won't work right as it suppresses all the tracing messages and swaps color channels for some operations. Please make sure to restore a vanilla build of libvdpau_trace.so on your system before filing a VDPAU bug against something else.

Update 2:

Here's another fix for issues 1 and 2 (it also includes GPU offloading of H.264 decoding):

1) Modify your Firefox/Google Chrome/Opera shortcuts this way:

Code:

VDPAU_NVIDIA_NO_OVERLAY=1 firefox

alternatively you can create /etc/profile.d/fix_flash.sh file with this content:

Code:

export VDPAU_NVIDIA_NO_OVERLAY=1

this way is even better as it guarantees that Adobe Flash Player will work in any web browser.

2) Create /etc/adobe/mms.cfg file and put this text into it:

Code:

EnableLinuxHWVideoDecode=1

P.S.

These two solutions do not solve the problems with sporadic Flash Player crashes and the scrolling of pages containing Flash charts.

P.P.S.

Since I enabled hardware acceleration in Flash, now Flash Player crashes every time when I try to jump to a certain portion of video or resize a video window in YouTube. :-(

The problem only happens when Flash uses software decoding but VDPAU for presentation; it swaps two arguments of the call to upload the video data into VDPAU in that case. The libvdpau-trace patch linked above fixes that. If it doesn't work for you, odds are you probably installed it wrong.

Ok, so I've been playing around with various stuff, and this is my conclusion:

First activate hardware decoding in Flash. To do so, put this in /etc/adobe/mms.cfg

Code:

EnableLinuxHWVideoDecode=1

This gets rid of the blue people, but still leaves the leaking overlay. Also, Flash tends to crash a lot. Not at youtube, but with other video players. So now I did this in the script that launches Firefox

Code:

export VDPAU_NVIDIA_NO_OVERLAY=1

And voila, no crashes. No leaking overlay either. The biggest plus: No need to hack the libvdpau library, which is especially nice for those who aren't used to compiling things (you really should learn though, it's a very useful skill to have).

Now a question for the Nvidia devs: What method is used for display now that I've disabled the overlay? Also, does this have a performance penalty, and if yes how big of a penalty?

(...)
And voila, no crashes. No leaking overlay either. The biggest plus: No need to hack the libvdpau library, which is especially nice for those who aren't used to compiling things (you really should learn though, it's a very useful skill to have).

A question: Do you take the acceleration hardware activated in the Firefox?

I say it, because it is necessary to activate 2 or 3 parameters to have it.